Naam said he expects the dollar to strengthen on positive third-quarter U.S. economic data and predictions of gradual Fed tightening. In turn, a weaker euro could relieve the ECB's need for new easing efforts on top of the massive stimulus package the central bank unveiled last March.
That announcement included lowering the deposit rate further into negative territory to -0.4 percent, an expansion of the asset purchase program to 80 billion euros (about $90 billion) per month and a new series of longer-term refinancing operations.
The chances of the ECB sitting tight in September are "helped by the fact that monetary policy is still becoming more accommodative as the measures announced in March continue to be enacted and kick in," said Howard Archer, IHS Global Insight's chief European and U.K. economist.
Economic data in the euro area have remained surprisingly resilient throughout the summer, despite uncertainties over how and when the United Kingdom could exit the European Union, said Societe Generale economist Anatoli Annenkov. But euro zone inflation remains well below the ECB's target of nearly 2 percent. In response to low inflation, Annenkov expects the ECB to announce an extension to the time frame for its asset purchases, which currently run through March 2017.
"It's really to reassure us all that they are able and willing to continue the program for a bit longer next year," Annenkov said. "I think a lot of people see that will be needed given the poor inflation outlook we have at the moment."
In the absence of a major policy announcement, Carsten Brzeski, chief economist at ING Germany, said he expects Draghi to strike a dovish tone in his news conference, in order to reassure markets that the ECB has the tools it needs to achieve its inflation mandate. The ECB president is likely to intensify his calls for governments to step in with structural reforms to help boost economic growth, Brzeski added.
"The ECB is getting a bit desperate," he said. "There is this growing concern, skepticism, about what central banks can still do."
Brzeski added that Fed tightening would mean a relatively stronger dollar and weaker euro, which could help the ECB move toward its macroeconomic goals.
"I don't see the Fed hiking in September but of course if they would, it would make life at the ECB easier," he said.